


Set it off

by Mix Stitch (Synph)



Series: DC ABO Series [4]
Category: DCU (Comics)
Genre: Alpha/Beta/Omega Dynamics, Anal Sex, Established Relationship, Flirting, Knotting, M/M, Mating Cycles/In Heat, Self-Lubrication, Weird Biology
Language: English
Status: Completed
Published: 2015-01-15
Updated: 2015-01-15
Packaged: 2018-03-07 18:09:33
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,965
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3178142
Author URL: https://archiveofourown.org/users/Synph/pseuds/Mix%20Stitch
Summary: <blockquote class="userstuff">
              <p>Sometimes, just being around Jason can be enough to set Tim’s heat off.</p>
            </blockquote>





	Set it off

**Author's Note:**

> This is a commission for stevebottoms ! Aaah! Major flipping thanks to my dear and darling cleromancy who is my go to for all things JayTim and who helped quell some of my persistent writing habits (namely redundancies and repetition).
> 
> This is actually set in the same A/B/O universe as A matter of timing (although you don’t have to read that one to get through this one and vice versa). Holy crap I loved writing this story! Loved it! 10/10 would write Omegaverse fic again in a heartbeat! (Also: holy crap it’s been a year since my last full blown Jason/Tim story. I need to get back on track with that ship, wow!)

Tim  _probably_  wouldn’t hate running herd on the rest of the family this time of the month if he didn’t  _have_  to take the downtime or risk going into heat in the middle of a sensitive operation.

There’s a part of his mind that actually enjoys getting to coordinate operations with Barbara back in her tower and bossing the rest of their pack around. Unfortunately, that part doesn’t stand a chance against the rest of Tim’s mind, the parts of him that chafe under the restrictions that being an omega automatically saddle him with.

"I can hear you huffing from all the way over here," Jason calls out from over by the exercise equipment on the far side of the darkened cave. "No one told you that you had to stay home tonight, you know?"

There’s a muffled noise, a muted thud that Tim thinks is related to Jason setting down the weights far harder than he’s supposed to, and Tim shifts in his chair, sending it spinning in a slow circle so that he can watch Jason make his way over to the bank of computers that Tim helped build himself.

Tim sniffs disdainfully.

"No one had to tell me  _anything_ ,” he says with a sharp note to his voice as Jason comes close enough that his scent hangs heavy in the air. “I’m due for a heat this week and I don’t like to be caught off guard while on patrol. This is safer.”

Jason shrugs. “Okay, but you can’t decide stuff like that and then sit around in a bad mood when you’re in the cave. It’s distracting.”

"Well no one told  _you_  to stay behind either,” Tim snaps, crossing his arms over his chest. “You could’ve gone out on patrol without me.” He huffs again, slightly louder as Jason moves even closer until he’s in front of Tim and looming over the chair. “If my mood is bothering you so much, you can leave.”

"As if," Jason says with a snort. "Do you really think that I’m going to leave you to brood all alone? What kind of alpha would I be if I couldn’t even spare some time to keep you too distracted to complain?" He ignores the way that Tim’s scowl deepens at that and then leans over him, bracing his hands on the arms of Tim’s chair, moving into Tim’s space until they’re almost nose to nose. "Is it working?"

Tim scoffs, ruder than intended, and then dips his head in a sharp but shallow nod.

"Yeah," he admits, voice low. "Now does that mean that you’ll let me get back to work?" Tim waves one hand in the direction of the computer screen that’s filled with monetary amounts that he has been working on tracing back to their original source through runarounds and bank firewalls in five different countries. "These numbers won’t crunch themselves."

Jason snorts , amused. He reaches out and cards his fingers through Tim’s hair, wisely saying nothing about the fact that Tim has foregone gel in it for the first time in  _months_. He takes his time with that touch though, dragging it out until it’s more of a caress and Tim can’t help leaning into the rub of Jason’s fingers over his scalp.

"You’ve been at it all night, Tim," Jason says in the quiet but forceful voice that Tim thinks is pitched at just the right tone to trigger some of his more annoying omega instincts — namely, the one about him behaving properly subservient in the presence of an alpha.  "Why don’t you take a break? We can go upstairs and spend the rest of the night in bed."

Tim frowns and shakes his head. “I can’t —”

There’s a moment there where Tim really can’t remember why he wants to stay in the cave, where the look on Jason’s handsome face — a mix of tender concern and the hunger that’s always present when they’re in the same room — makes his head feel a bit heavy and his heartbeat pulses at double time in his chest.

When he shakes his head, it seems to clear. Tim manages a scowl for Jason.

"Quit it, Jason," Tim says, sharply.

Jason doesn’t flinch, doesn’t even glance away from Tim’s face as if silently admitting guilt. Instead, he smiles. Slow, wide, it’s the kind of smile that never fails to make Jason look younger even as it adds a faint predatory tint to his actions.

Tim pushes down the urge to smile back at Jason. He pulls away from the heavy weight of Jason’s fingers in his hair and settles firmly in the massive office chair.

“ _Jason_ ,” Tim says again. It comes out more like a whine than Tim wants to hear and when he frowns again, it’s at himself. “I know what you’re doing.”

Jason leans back slightly, still smiling. “You do, huh?”

Tim licks his lips, unbelievably tempted by that smug look on Jason’s face. However, Tim knows better. Giving in might feel good — no,  _will_  feel good — but then Tim’ll have to deal with the fact that he’s used up precious time that could’ve been used to wrap up his case before his heat hits.

Shaking his head, Tim tries to fight back the biological urges that make him want to bow his head or bare his neck or some other kind of archaic foolishness that Jason doesn’t even  _like_.

"I still want to get more work done on this," Tim says and that’s one hundred percent the truth. He finally manages a smile for Jason and is pleased when Jason’s smile only widens and his alpha reaches out to stroke a heavily callused hand through his hair. "Will you take a rain check? For later, I mean."

After all, it can’t possibly take Tim more than an hour or two to get to the point where he’d feel comfortable leaving his work for someone else to finish in case a fun distraction with Jason managed to set off his heat a few days early.

"I’ll hold you to it," Jason says, smiling widely enough that Tim can see the chipped left tooth that serves as a reminder of how their relationship doesn’t at all match that of most of the alpha/omega couples that they know. After all, most omegas wouldn’t dare spar with their alpha, much less hit them hard enough to crack their tooth.

Jason steps back proper and then jabs his left thumb in the direction of the weight machines and workout mats that take up a full section of the floor on this side of the cave. “I’ll be over here working out for a few more hours. Just call me if you need me, okay?”

Tim nods, biting his lip as he does so.

"Okay," he mutters, telling himself that it’s not a lie if he intends to do it.

Thankfully, Jason doesn’t call him out on that even though the indecision has to be plain on his face. Jason only nods and heads back to the exercise machines, leaving Tim alone with his computer, his numbers, and an uncomfortable prickling sensation low in his belly that he  _really_  doesn’t want to think too much on.

*

Tim barely manages to make it through an hour of work.

The prickling in his belly starts to turn into a sharp ache, increasing in increments until the only thing that Tim can focus on is the sensation of sweat sliding down the nape of his neck and the scent of Jason’s sweat in the air. It takes him a minute to get it, to get the reason behind him sitting in front of his computer and not even registering the text on the screen.

His heat has come early. That’s the only thing that makes sense. Tim can’t think of anything else that’d have him sweating and all but salivating when Jason’s scent wafts over to him. Normally, his sense of smell is middling at best. That he can practically  _taste_  Jason on his tongue despite several yards’ distance between them?

Well, it’s not the  _best_  sign.

Tim thinks about calling Jason over, frowns, and then pushes out of his chair to stand on legs that feel as if they’re seconds away from toppling over. Standing up, Tim can feel even more of the signs of his heat. He feels slick, wet in a way that he hasn’t managed to get used to even after five years of relatively regular heats. He feels more sensitive too, like his skin is a size too small and itchy in a way that feels  _good_.

Now, it’s not like Tim is starved for touch, not with Jason around, but the heat makes him a little needier, a little hungrier. Tim wants touch now, craves it like he rarely does outside of his heats, and the only person he can think of that can and  _will_  satisfy the ache in him is on the far side of the room.

Walking is… not fun.

By the time that Tim makes it across the floor to where Jason is busy doing crunches on one of the thicker mats, he’s hard against his sweats and every step that he takes reminds him of how slick he gets just from Jason’s nearness.

Jason doesn’t even seem to notice that anything is wrong until Tim’s actually in his lap. Tim is fast when he wants to be and Jason’s relaxed guard means that when Tim wriggles into his lap and loops his arms around Jason’s neck, that Jason goes with it, mouth opening up underneath Tim’s own as his dick rapidly fills out and presses boldly against the front of his shorts.

When the kiss breaks, Jason’s eyes are dark with desire.

"I take it that you’re done with work now?" Jason asks, one hand settling against Tim’s right hip with a proprietary squeeze that makes Tim squirm against him. At the hasty nod that Tim manages, Jason grins and the hand he has on Tim’s hip shifts to his ass, squeezing just hard enough to force Tim’s breath out in a stuttered cry against his throat.

"Jason!" Tim croons in a voice that he barely registers as his. He’s hard enough that it almost hurts and so slick that the thought of simply burning these pants when they’re done instead of letting Alfred  _near_  them actually seems like a good idea.

The hand Jason has on his ass pauses mid-squeeze and something about Jason’s scent changes from the almost addictive sweetness of arousal to something bitter that makes the hair on the back of Tim’s neck stand.

"Shit," Jason hisses a moment later, bolting up and nearly unseating Tim from his lap in the process. "You’re in heat." He leans in so that he can sniff at Tim’s neck and then lick at it, the touch of his tongue more of a personal quirk than anything that alpha/omega couples  _have_  to do. He presses his nose and mouth to Tim’s skin in turns, nuzzling and mouthing at the skin there until Tim is a panting  _wreck_ and Jason isn’t that much better.

"We have to go upstairs," Jason says, pulling away from Tim’s throat and the marks he always leaves there.

Tim shakes his head. “No,” he says, almost pleading as Jason makes to move away from him. “Why?”

One corner of Jason’s mouth quirks upward with a smirk. “Unless you’ve suddenly gotten a  _thing_  for showing off, I don’t think you’ll thank me for letting you get naked in the cave.” He gets to his feet and then hauls Tim up right after him, pulling him into his arms before Tim can try and talk him into staying in the cave.

After that, it’s only a matter of getting Tim into the elevator and upstairs.

*

"No one’s scheduled to come back to the cave for hours," Tim mutters as he watches Jason strip from his vantage point on the king-sized bed in his room. "We could’ve stayed —"

Jason drops his shirt to the floor and then rolls his eyes. “And you’d’ve kicked my ass for it when your heat broke,” he points out. “Trust me. This is a better idea.”

Once naked, Jason joins Tim on the bed, pressing Tim down underneath his weight and effectively cutting off any further argument by the press of their mouths together in a sloppy kiss. The slide of their tongues together and the fit of their lips together feels right, feels good and perfect.

But then Jason pulls out of the kiss and then pushes Tim back down until he lays sprawled across the bed, naked with his fair skin flushed with desire.  Tim nearly  _dies_  from the frustration.

"Are you — are you just going to stare at me?" Tim’s voice is rough with want. He braces his weight on his elbows and watches as Jason curls his fingers in against his right ankle, rubbing the skin there until Tim has to bite back a whimper as his heat amplifies the touch.

"Spread your legs," Jason says instead, licking his lips slowly. When Tim’s thighs part, Jason moves into that space, kneeling between Tim’s legs as his gaze focuses there. He presses his fingers to Tim’s hole, to that small pucker that opens up for him with just the lightest touch.

In no time at all, Jason has Tim’s body slick and open around his fingers. Every forward press of his hand makes Tim arch his back and squirm across the sheets, digging his heels into the mattress as he spreads his legs even wider. Caught in the throes of his heat, Tim doesn’t seem to have any shame. At least, not to Jason, whose fingers he’s riding as if he couldn’t imagine having anything else inside of him.

"Fuck," Jason says as he feels Tim’s muscles clench tight around his fingers.

Tim manages to utter a choked-sounding burst of laughter at that. He lets his head drop back against the bunched up sheets underneath him. “Y-yeah,” he says, his voice coming out shaky from the pleasure that Jason keeps teasing out of his heat primed body. “Isn’t that what we’re supposed to be doing?”

"Smart mouth," Jason says with a smirk, twisting his fingers inside of Tim one last time just to pull another shaky cry from his omegas lips. He pulls his fingers out of Tim’s absolutely  _soaked_  hole and then, reaches down to hold his dick steady as he fits the head of it against Tim’s hole.

Tim reaches for Jason on that push, wrapping his arms around his alpha’s broad shoulders and holding him fast as Jason fucks into him hard enough to leave his breath catching in his throat as his dick twitches between their bellies.

"Shut up and fuck me," Tim growls, ragged edged nails scrabbling over the scarred skin of Jason’s back. He groans when, a moment later, Jason gives him what he wants, screwing into him hard enough to make Tim whine and clench as his body produces even more slick to ease the way. Like this, the fucking is easier and yet —

Harder.

Jason fucks Tim hard, snapping his hips against Tim’s ass and drawing out more and more of those cries that Tim can’t stop himself from uttering. Tim knows that neither of them is going to last long. He can already feel Jason’s knot threatening to swell as he thrusts into Tim’s hole like there’s nowhere else that he wants to be.

At the first sign of Jason’s knot, Tim whines and then comes all over their stomachs, his head dropping back against the mattress as his dick spurts come out to cover their skin and smear over his abs as Jason ruts into him harder.

"Oh —  _oh_ ,” Tim moans as Jason’s knot starts to swell inside of him, opening him up until it aches and  _Tim can’t think_  —

Jason surges forward, mouth hot against Tim’s throat as his knot locks them together amidst the sweaty tangle of sheets surrounding them. He bites down hard, teeth pressing in enough to bruise as Tim goes limp beneath him, body going loose and languid at the pleasure that the knot brings him.

After a while, Tim’s moans peter off into a soft silence.

Jason, still tied to Tim with the knot, nuzzles a kiss to one side of Tim’s jaw. “You okay, Tim?”

Tim tries to nod his head but only ends up flopping it lazily from side to side. Eventually, he manages to string a simple sentence together.

"Y-yeah," Tim says in a muzzy murmur that Jason has had plenty practice in deciphering. "I’m good. Real good." Tim’s eyebrows scrunch together in the seconds afterwards and he frowns. "Wait. No I’m not. You’re heavy, Jason."

Jason laughs against Tim’s throat and then carefully rolls them over until Tim is on top, their bodies still joined by Jason’s knot.

"Is that better?"

Tim huffs softly but then presses close, allowing Jason to stroke one hand over the sweaty side of one thigh.

"I guess so," Tim concedes after several seconds stretch with silence. "But we’re using some other position next time." He shifts, raising up so that he can scowl at Jason. "Got it?"

Jason grins. He just can’t help himself, not when Tim is still so bossy despite barely being out of the first round of his heat period.

"Yeah, yeah," Jason drawls. "I understand." He pulls Tim back down to lie against his chest as his knot begins the slow, tedious process of softening, trying to lull Tim into a much needed nap before the second round starts and all sense is lost in the rut. "If you can think straight next time,  _you_  can pick how we fuck.”


End file.
